425 valve covers

ijasond · 07-31-2007, 11:57 AM

My cars stock valve covers are baffled(66 425 4bbl), I want to go back with chrome covers when I have it rebuilt, do I have to have the baffled valve covers? what is the difference? Thanks.

Oldsguy · 07-31-2007, 01:23 PM

The baffles will prevent oil blowby, if you use valve covers without baffles you may experience oil on the outer surfaces of the covers and on the top of the engine. There was another post here about someone who had trouble with this and I think the correction was using baffled valve covers.

ijasond · 07-31-2007, 02:20 PM

I was told that I needed to use them. It's just in my nature to always want to know why as well. Thanks!

Oldsproject · 07-31-2007, 05:52 PM

Be careful when ordering the valve covers. I ordered standard chrome valve covers w/baffles from Mondello and they don't fit. The problem is that on the 425 I have the breather holes are in the center and the ones from Mondello are on each end or offset. The baffles on the offset covers hit the rockers as the spacing between them isn't wide enough. Not sure if this is true on all 425's or if the problem was caused because I changed the stock valve train to a comp cams system. Something you should check first though.

ijasond · 08-01-2007, 05:40 AM

thanks, I was thinking about doing the same thing, though I'm just going to be cruising & showing off so I don't know if it is worth the effort or the extra money.

don71 · 08-01-2007, 02:19 PM

I recently installed some roller rockers on my 455. I found it to be true, that some of the rockers hit the baffles, just barely and only on a few. I' m using factory valve covers.

I did'nt like that, so I had three choices. Dent the baffles just were they made contact, remove the baffles, or double up and glue two sets of gaskets.

I chose to remove my baffles. Actually, I had a set allready just in case.

So far, I have driven about 200 miles. No leaking or oil consumpton........ yet, and don't expect any. We'll see.

frdmftr · 08-01-2007, 02:22 PM

Good info. I have Edelbrock chrome covers and do get some blow-by. I like the look (when the hoods up at a show) and carry a roll of paper towels.

FOUROUTAFIVE · 11-09-2007, 12:52 AM

Quote:

Originally Posted by frdmftr

Good info. I have Edelbrock chrome covers and do get some blow-by. I like the look (when the hoods up at a show) and carry a roll of paper towels.

The 66 delta 88 I miight be getting has those edelbrock covers. I was wondering if this could be the reason also that I'm getting that knocking sound on the top of the valve cover

CHRISH8846 · 11-12-2007, 10:28 AM

200 miles may not be enough to show any problems,I had no baffled valve covers and was running a pcv valve and found out that I was pulling oil thru the valve covers and thru the pcv valve and actually causing a carbon build up on my intake valves. it caused a oil consumption problem that I was not aware of until i elimanated the pcv valve,I thought 1 qt evey 750 miles was ok on a performance engine, after I elimanated the pcv valve I have run almost 2k and have not had to add any oil.fyi I have no discernable blow by.

07-31-2007, 11:57 AM	#1 (permalink)
ijasond Senior Member Join Date: Feb 2007 Posts: 102	425 valve covers My cars stock valve covers are baffled(66 425 4bbl), I want to go back with chrome covers when I have it rebuilt, do I have to have the baffled valve covers? what is the difference? Thanks.

07-31-2007, 01:23 PM	#2 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 3,167	The baffles will prevent oil blowby, if you use valve covers without baffles you may experience oil on the outer surfaces of the covers and on the top of the engine. There was another post here about someone who had trouble with this and I think the correction was using baffled valve covers. __________________ Dan '77 Cutlass Supreme '46 2 door

08-01-2007, 02:19 PM	#6 (permalink)
don71 feed the pig Join Date: Jun 2007 Location: Central Missouri Posts: 178	I recently installed some roller rockers on my 455. I found it to be true, that some of the rockers hit the baffles, just barely and only on a few. I' m using factory valve covers. I did'nt like that, so I had three choices. Dent the baffles just were they made contact, remove the baffles, or double up and glue two sets of gaskets. I chose to remove my baffles. Actually, I had a set allready just in case. So far, I have driven about 200 miles. No leaking or oil consumpton........ yet, and don't expect any. We'll see. __________________ 1971 Cutlass S 455/th400 3.23 rear.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

07-31-2007, 02:20 PM	#3 (permalink)
ijasond Senior Member Join Date: Feb 2007 Posts: 102	I was told that I needed to use them. It's just in my nature to always want to know why as well. Thanks!

07-31-2007, 05:52 PM	#4 (permalink)
Oldsproject Member Join Date: Mar 2007 Posts: 55	Be careful when ordering the valve covers. I ordered standard chrome valve covers w/baffles from Mondello and they don't fit. The problem is that on the 425 I have the breather holes are in the center and the ones from Mondello are on each end or offset. The baffles on the offset covers hit the rockers as the spacing between them isn't wide enough. Not sure if this is true on all 425's or if the problem was caused because I changed the stock valve train to a comp cams system. Something you should check first though.

08-01-2007, 05:40 AM	#5 (permalink)
ijasond Senior Member Join Date: Feb 2007 Posts: 102	thanks, I was thinking about doing the same thing, though I'm just going to be cruising & showing off so I don't know if it is worth the effort or the extra money.

08-01-2007, 02:22 PM	#7 (permalink)
frdmftr Freedom Fighter Join Date: Feb 2007 Location: Nine Mile Falls, Washington Posts: 122	Good info. I have Edelbrock chrome covers and do get some blow-by. I like the look (when the hoods up at a show) and carry a roll of paper towels.

11-12-2007, 10:28 AM	#9 (permalink)
CHRISH8846 Junior Member Join Date: Jan 2006 Location: Summerville SC Posts: 8	200 miles may not be enough to show any problems,I had no baffled valve covers and was running a pcv valve and found out that I was pulling oil thru the valve covers and thru the pcv valve and actually causing a carbon build up on my intake valves. it caused a oil consumption problem that I was not aware of until i elimanated the pcv valve,I thought 1 qt evey 750 miles was ok on a performance engine, after I elimanated the pcv valve I have run almost 2k and have not had to add any oil.fyi I have no discernable blow by.